Composite part layups may be cured using tools that are heated to a predetermined temperature required to cure the layup, often referred to as the “cure temperature”. In some cases, the layup is cured within a matched set of tools that compress the layup during the cure process in order to produce a consolidated, net-shaped part. The cure process is sometimes complicated by part layups that use certain types of binder resins, such as thermosetting resins that undergo exothermic reactions during the cure process. The exothermic reactions generate heat that may elevate the temperature of the layup above the cure temperature. Because of the relatively large thermal mass of conventional cure tools, the heat added to the layup by an exothermic reaction may not be quickly or easily removed, which may result in less than optimal curing of the part layup. The problem of extracting excess heat caused by exothermic reactions in a layup may be more challenging in part layups that have a combination of both relatively thin and thick areas, since an attempt to reduce the temperature of the layup in thicker areas may reduce the temperature of the layup in thinner areas to a level that is below the desired cure temperature.
In the past, attempts to control part layup temperature variations due to exothermic reactions have been limited to using relatively slow temperature ramp-up profiles, however this approach may be time consuming and may reduce throughput in production environments. Additionally, in some applications, it may be difficult to maintain a relatively slow heating rate, and any error in the temperature during the temperature ramp-up may result in less than optimal curing of the part layup.
Accordingly, there is a need for a method and apparatus for curing a composite part layup that allows temperature control over individual areas of the part in order to compensate for the localized effects of exothermic reactions, while avoiding the need for slow thermal cycles used for curing.